1. Field of the Invention
The present invention relates to a cage which is inserted between vertebral bodies of a cervical vertebra or spine during an operation for treating a cervical disc disease, myelosis, or fracture of the cervical vertebra or spine, and more particularly, to a cage including upper and lower spikes which are attached to a clip inserted into a main body of the cage, unfolded to protrude from the top and bottom of the main body, and locked to vertebral bodies of a cervical vertebra or spine positioned at the top and bottom of the cage such that the cage is fixed between the vertebral bodies.
2. Description of Related Art
In general, an operation of inserting an artificial compensation-chain cage between vertebral bodies of a cervical vertebra or spine is performed in order to treat a cervical disc disease, myelosis, or fracture of a cervical vertebra or spine in the orthopedics department or neurosurgery department. More specifically, an operator removes a cervical disc of a diseased part so as to eliminate compression of nerve, and inserts the artificial compensation-cage to recover and maintain the interval of the part from which the cervical disc has been removed.
Such a cage is likely to be moved within the intervertebral space by stress applied when the patient moves. Thus, an additional unit must be provided to prevent the pivot of the cage while preventing the movement of the cervical vertebra or spine within the intervertebral space.
According to Korean Patent Laid-open Publication No. 10-2011-33707 which has disclosed a cervical vertebral body fusion device, Korean Patent No. 900991 which has disclosed a cage for spinal implant, and Korean Patent Laid-open Publication No. 10-2011-11049 which has disclosed a fusion cage between vertebral bodies, a cage is inserted into a part from which an intervertebral disc has been removed, and a reinforcement plate having a predetermined length is fixed to a cervical vertebra or spine through a screw, thereby preventing the displacement of the inserted cage.
In the above-described techniques, however, the reinforcement plate is fixed at the front of the cage through the screw. Thus, the head of the screw inserted into the plate or a part of the plate may protrude more than protruding parts of the cervical vertebra or spine, which are positioned at the top and bottom of the part from which the intervertebral disk has been removed and in which the cage is installed. In this case, according to a force applied when a patient moves with time, the cage may be moved or pivoted within the intervertebral space such that the protruding head of the screw within the intervertebral space comes in contact with blood tissues or nerve tissues passing through the cervical vertebra or spine. Thus, there is a demand for the development of a more stable cage.
Furthermore, the plate and the screw are used to fix the cage. In this case, it is extremely difficult to fix the plate through the screw in such a small intervertebral space, while much attention is needed. Thus, special technical skills are required for an operator.